Keep track of items on robot and only allow for bidding on pickup task if we got a free compartment remaining (#518)

Posted by @Odin-byte:

As stated in the title, is there a current way to allow RMF to keep track of the number of available compartments on a robot and account that for pickup tasks?

If not what would be the place within the current code to implement this?

I am currently working with free fleet and the full control adapter.